Annealing furnace



March 8, 1932. R. H. STEVENS ANNEALING FURNACE 6 Sheets-Sheet 1 Filed Feb. 5, 1930 F FE m T N E V m March 8, 1932. R. H. STEVENS ANNEALING FURNACE Filed Feb. 5, 1950 6 Sheets-Sheet 2 0 4 INVENTOR Q; ii. E 55 0a.

ATTO EY March 8, 1932.

R. H. STEVENS ANNEALING FURNACE 6 Sheets-Sheet 5 Filed Feb. 5, 1930 fix AEORNIEY March 8, 1932. I STEVENS 1,848,281

ANNEALING FURNACE Filed Feb. 5, 1950 6 Sheets-Sheet 4 V m z INVENTOR March 8, 1932. R. H. STEVENS ANNEALING FURNACE Filed Feb. 5, 1950 6 Sheets-Sheet 5 INVENTOR ATTOR March 8, 1932. STEVENS 1,848,281

ANNEALING FURNACE Filed Feb. 5, 1930 6 Sheets-Sheet 6 2g INVENTOR IZE $220606.

Patented Mar. 8, 1932 m mm mes . RICHARD H. STEVENS, F BALTIMORE, MARYLAND, ASSIGNOR TO BETHLEHEIVI STEEL COMPANY A CORPORATION OF PENNSYLVANIA .ANNEALING FURNACE My invention relates to annealing furnaces and is designed more especially for heat treating wheels or other circularforg ngsor blanks where the process includes an anneal- Sing or drawing back? after quenching at relatively low temperatures which are usually difficult tocontrol. i

Although 'wheels,L ircular forgings or blanks may be treated in my furnace I willin this specification in order to avoiduseless repetitionsherein refer more specifically to the articles treated as a wheel with the urn derstanding however that any circular disk, blank or circular forging niaylbe treated in 5 a similar manner in my furnacea-iid is meant by that term.

One of the objects of my invention is to produce a furnace of the inuflle type which s so designed that a uniform temperature may be obtained and controlled and regulated within close limits, and in which atmospheric air is excluded from the article or articles treated except during the short periodsof time the articles are entering or leaving the furnace. I I Another object of my invention is to pro} duce a muffle furnaceinto which circular articles are adapted to be chargedat one 39 end and fed forward by gravity'through the oven in a plurality of rows with means for supporting and guiding the articles as they are progressively fed through the oven until they are taken out of the opposite end of the furnace. V

Another object of my invention relates'to theinanner of adjusting the guiding mechanism for the articles. I r

Another object of niy invention relates to 7 i the braking and bufiing mechanism for retarding or stopping the movement of the wheels or circular for 'ings as'they are fed through the oven.

Theiinv enti'on has for further object to' provide an annealing furnace 'having the new and improved features and consisting of the 7 novel arrangements, combinations and con structions shown in the drawings hereto an nexed and which will be more fully described a0, and claimed in the following specification.

on the line 6 6 of Fig. 2;

7 Referring now to the accompanying six sheets of drawings: I

7 Fig. 1 is a horizontal section through the,

furnace taken on the line 11 of Fig. 2;

Fig. 2 is. a vertical longitudinal section taken on the line 22,of 1; r Fig. 3 is a detail sectional view-of the ,ad-. ju'st-ing screw for the upper guide bars taken on the line 3+3 of Fig. 4; p I i i Fig. t is a detail side elevation view of the adjusting screw for the upper guide bars, the attaching bracket being shown in section and one side of the bifurcated lever arni being shown broken away to more clearly show the manner of construction Fig. 5 is an elevation ofthe charging end of the furnace taken on the line 55 of Fig. 2, the charging cradle being removed; F 1g. 6 IS a vertical transverse section taken D1g'. 7 is a vertical longitudinal section of a portion of the charging end ofthe oven drawn on a larger scale and taken on. the

same line as Fig.2; Fig. 8 is a transverse section view through the discharge end of the oven takenon the line s s ofFig. 2;

' Fig. 9 is an enlarged detail transverse sectional view taken on the line 99 of Fig. 7; I Fig. 10 is a detail view of one of the hand wheels and screw adjustment for one of the brakes; and v V Fig. 11 is an enlarged detail transverse sec-v tion through the charging cradle.

Referringnow to the characters of reference on the drawings: The numeral 1 indicates a cylindrical shell or casing forming the oven which is mounted in a downwardly inclined position from the charging to the discharge end and through which the wheels, circular forgings or blanks 2 are placed for heat treating, the shell being surrounded at the sides and supported at each end on the masonry brickwork 3 which is suitably stayed and supported by steel buck-stays and bind angle rings 6, and 7. Theoven is arranged for two lines of wheels 3 which roll on their treads by gravity when placed on the inclined supporting track rails 8 and are guided at the sides by the guide rails 9 and 10. The bottom guide rails 10 and the supporting rails 8 are fixed and are secured to and supported on the structural steel framing 11 welded or otherwise secured in any approved manner to the inner side of the cylindrical shell 1. The upper guide rails 9 are supported by links 13, one end of each of said links 13 being pivotally attached to the guide rails 9 while the opposite ends are pivotally swung by means of shafts 12 from the steel framing 11. This provides for adjustment of the upper guide rails 9 to a height suitable to the diameter of the wheel being heat treated. This adjustment is made by a screw I threaded rod 14 j ournaled in a trunnion hearing 1 5 and supported by a bracket 16 attached to the outside of the cylindrical shell 1 and operated by a double acting ratchet lever 17 at the discharge end of the furnace. The

' threaded rod 14 works in a trunnion nut 18 which is carried between the bifurcated legs of a. lever 19 on shaft 20 which is ournaled in the cylindrical shell 1 and on the steel framing 11, and transmits its motion through the levers 21 mounted on the shaft to the top guide rails 9 which causes the said guide rails 9 to swing through an are but keeping parallel to the axis of the shell 1. In operating the movable guide rails I may operate both pairs independently with a separate ratchet lever or in conjunction with each other'as desired.

The inclination of the supporting tracks and guide rails is such that when the furnace is full of wheels, each touching the adjacent one the force of gravity will counteract the friction andwill cause the Wheels to roll down the incline slowly. As one wheel is taken out at the discharge end, the other wheels automatically roll down towards the discharge end of the oven. The inclination of the supporting tracks and guide rails for operating the furnace oven full is too great when only one or two wheels are on the tracks and to overcome the high velocity which would develop in rolling down the track from the charging to the discharging end of the oven when starting up with the first few wheels brakes are provided over each track consistingeach of a heavy bar 22 pivoted at one end by means of a bracket 23 to the shell 1, and

a suspended by a chain 24 which extends upwardly through an opening in the shell 1,

into a collar 25 and has a screw threaded eye bolt 26 for receiving the screw threaded nut ofa hand wheel 27 as indicated in Figs. 2 and 10 of the drawings. The bars 22 may be adjusted vertically until they come in contact with the top surfaces of the wheel rim or tread, the friction between the wheels and the bars being sufiicient to retard the velocity of the wheels or to stop them completely if desired.

In addition to the brakes a bumper 28 is provided at the discharge end of each track consisting of vertical structural steel members 29 having their lower ends embedded in the concrete foundation. Cross members 30 connect the upper ends of the structural steel members 29 together and receive the shock transmitted to the bumpers from the upturned ends 31 of the track rails 8 to vertical members 29. The upturned ends of the rails 8 are kept clear of the end plate 5 of the shell and projecting pieces of the bumpers pass through holes 32 in the end plate 5 and bear upon the rail only, thus protecting the end plate and allowing-all the shock to come on the bumpers.

' The manner adopted for obtaining the vertical adjustment, by swinging the top guide rails 9 on a series of links 13 involves a condition at the entering end ofthe oven in which a spaceoccurs between the end of the top guide rails 9 and the end plate 4 of the oven, which must be bridged over to form a continuous guide for the wheels. This space is necessarily longer when the guide rail is in its lowest position.

- The mechanism toform this end guide is shown more clearly in Figs. 7 and 9 of the drawings and consists of short steel blocks 33 machined to slide on the guide rails 9 and having its guiding surface in line with the rail. The guide blocks are each backed up and kept in line by the angles 34 fixed to the end plate 4 and the steel framing 11. The guide blocks 33 are each raised and supported vertically to the required height by the ends of the guide rails 9 and it is kept parallel to guide rail by means of the links 35 and 36 forming a parallel motion device and having the fixed fulcrum points at 37 and 38 on the end plate 4 and steel framing 11 respectively. The links 35 and 36 are pivoted together centrally as at 39, while the inner ends of said links are movable and pivoted to short connecting links 40 and 41 the opposite ends of which are pivotallv secured to the guide blocks 33 and the shaft forming the fixed fulcrum point 38 on the steel framing 11. Links 35 have their forward ends secured to the fixed fulcrums 37 and supported by brackets attached to the end plate 4 while the forward ends of links 36 are pivoted directly to the guide blocks 33.

At the entering or charging end of the oven and outside of the cylindrical shell 1.

are provided cradles. or receptacles 42 in which the wheels are placed before being rolled into the furnace. This is built of structural steel and plates, and is arranged to facilitate the release of the hooks used in lifting the wheels. The upper guides 43 are movable and may be bolted at any convenient height to suit the diameter of the wheels ;being treated} v g I V The end plate 4 is formed withopeningslet at the entering end of the oven through which the wheels enter the oven and are provided withdoors 45 each adapted to swing laterally from pivotal point 46 at the top of each door. These doors are mechanically operated by air cylinders 47 mounted on theend plate 4, which are opened only to allow a'wheel to pass through, and then closed immediately to exclude the'air. I

The'discharge doors 48 are located on the top of the lower end of the cylindrical shell 1, and are of light construction and operated manually. The'wheels are removed in any approved manner as by meansof a hook operated by anelectric hoist running on an I-beam monorail (not shown). The object of locat ing the discharge doors thus is to secure a 7 means of removing a wheel which would within the lower portion of the cylindrical automatically allowthe following wheels to roll down to the discharge end'of the oven, theend wheel beingalways i n-a position where it can be readily removed. The dischargerdoo'rs are keptclosed,except'when removing a wheel, to exclude air. A vertical divisional plate 49 extends longitudinally temperature, it being important that as nearly as possible a constant temperature be maintained throughout the entire period the wheels are under treatment.

Allowance is made for the freeexpansion and contraction of the cylindrical shell' 1 with reference to the furnace setting, the shell being anchored at the discharge end and free to expand at :the chargingend. The cradles 42 for receivingthe wheels are bolted to the shell 1 but are not bolted to the'foundation', being arranged to slide on a plate 51 on top of the foundation. To give additional support to the brickwork at the entering or charging end an angle end plate '52 is built aroundthe brickwork on which the shell is free to move.

For heating the oven oil is preferably the fuel used, the oil burners 53 are inserted through openings5e in the furnace side wall. These burners-are placed at the end of each of the four combustion chambers 55 located beneath the ovenand-heating chamber 56 which surrounds'the same and each is separated from the heating chamber by a thick'arched roof' 57. The hot gasesof combustion from 22 and the charging end of the oven.

' the combustion chambers 55 are led upwards through the tines 58 to the heating chamber 56 containing the cylindrical shell 1 which forms the oven, which they enter from the top corner near the roof. The hot gases as they pass through the heating chamber divide and pass around both sides of the shell to the-conduit fine 59 leading to the stack through the flo port openings 60 built on each side of the V f combustion chambers 55. A damper plate 61 is placed over each of the port openings 60 which lead .to the stack and serve toequalize the combustion and the flow of hot gases around theshell. Each of the arched roofs 57 over the combustion chambers is made of heavy construction and includes a course of insulating brick 62. The object ofthis is to prevent the intense heat in the combustion chambers from passing through thereof and interfering with the natural flow of the hot gases of combustion around theshell 1, by

setting upaflow of gases counter to those descending to the flue port openings 60. The

furnace rests on a concrete foundation 63 over a course of brokenslag 6% thus providing a drain to keep the fines dry at allztimes.

Having thus givein adeseription of myinvent-ion, I will now describetheoperation.

Assuming that the parts are in the positions shown inthe drawings wheels are lifted preferably directly from the quenching tank 65 into the cradles 42 andplaced on the track rails 8 at the charging end of. the' oven the doors 45 are opened'by means of the air cylinders 4:7 and the wheels will then roll by gravity through the door openings 44 in the end plate 1 into the oven until they engage the brake bars 22 or the edge ofthe last wheel charged intothe oven. Either one or both lines of wheels may be chargedat one time into the oven on track rails 8 or they may be charged intermittently on each track if desired. In fstarting'the charging operation .when the oven is empty the brake bars 22 will beset at therequired heightto engage the tread of the first wheel and preferably stop it this operation of'charging wheels intothe oven will engage the edge of thefirst wheel charged,

this operation of charging wheels into the oven continues'until the oven 15 filled withwheels on the track'rails 8 between the brake bars As the wheels are charged into the oven the heated tion chambers 55 by means of the burners 53 are led upwardly through the lines 58 to the gases of combustion supplied to the combus- I heating chamber 56 containing the cylindricalshell 1 which forms the oven. The hot gases from the fines 58ers divided in the heating chamber and pass around both sides.

of theshellof the oven and pass to the stack conduit flue 59 through the port openingsSO.

As the hot gases'pass around. the shellofthe oventhe wheels are heated to the desired temperature, which continues until the forward iiio' wheel has received the proper heat treatment which can be ascertained by the series of pyrometers 50 connected to the oven at spaced intervals. lVhen the forward wheels receive the desired heat treatment the brake bars 22 are raised out .ofcontact with the wheels which will alloweach line of wheels on the track rails 8 to roll downwardly by gravity until the for:

ward wheel engages the upturned ends 31 of the track rails 8 each of which is backed by a bumper 28, at the discharge end of the oven. One of the doors at the discharge end of the oven is then opened and a wheel lifted out of the oven,this will allow the line of wheels on that track to be automatically fed forward the width of the wheel discharged and another wheel may then be fed into the charging end of the oven. The other door at the discharge end of the oven may then be opened and a wheel lifted out from the other track from the forward end of that line of wheels and another wheel fed into the oven at the charging end of the oven. This operation may be continuously repeated as the wheels are fed into the oven and discharged in sequence. The doors at the charging and discharging ends of the oven are open only during the short intervals of time it takes to charge or discharge the Wheels from the oven and then immediately closed so to exclude atmos heric air from the wheels being treated. n order to protect the wheels on the I track on one side from being cooled by an inrush of cold air when the door on the other side is opened, a central vertical plate 49 extends longitudinally of the cylindrical shell 1 between the doors and two lines of wheels and divides it into two parts so that one door may be opened and a wheel removed without affecting the temperature of the forward wheel-on the opposite track.

In illustrating my invention I have designed a. furnace having an oven with two lines of track for the wheels but the same principle would apply equally well to a furnace having an oven with more than two lines of track or with only one if desired.

Although I have described and illustrated my invention in considerable detail, I do not wish to be limited to the exact and specific details thereof, as shown and described, but may use such modifications in, substitutions for, or equivalents thereof, as are embraced within the scope of my invention, or as pointed out in the claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. An annealing furnace comprising a stationary cylindrical shell forming an oven, a heating chamber surrounding the cylindrical shell, a combustion chamber having aflue leading to one side of the heating chamber above the oven, :1 burner adapted to furnish heated gases for heating the combustion chamber and heating chamber, means for conducting the heated gases from the flue around the cylindrical shell, and a port openingbelow the oven communicating with a conduit leading to the stack for the off gases.

2. An annealingfurnace comprising a stationary inclined cylindrical shell forming an oven, a track within the cylindrical shell on which annular articles may roll from the charging to the discharge end of the shell and means mounted above the track and in spaced relation thereto for guiding the annular articles on the track.

3. An annealingfurnace comprising a stationary inclined cylindrical shell forming an oven, a track Within the cylindrical shell on which annular articles may roll from the charging to the discharge end of the oven, 8. fixed means mounted above the track for guiding the annular articles on the track, and movable means mounted above the fixed guiding means for guiding the annular articles.

4. An annealing furnace comprising a stationary inclined cylindrical shell forming an oven, a track within the cylindrical shell on which annular articles may roll from the charging to the discharge ends of the oven, fixed and pivoted movable guides mounted above the track within the oven for guiding the annular articles, and means for verti cally and longitudinally adjusting the movable guides.

5. An annealing furnace comprising an inclined cylindrical shell forming an oven, a framing within the cylindrical shell, a plurality of tracks supported by the framing within the cylindrical shell on which annular articles may roll from the charging to the discharge end of the oven, fixed guides on opposite sides of the tracks attached to the framing for guiding the annular articles on the tracks, guides supported by the framing adapted for vertical movement on each side of the articles treated, and means for adjusting the I movable guides.

6. An annealing furnace comprising a stationary inclined cylindrical shell forming an oven, a heating chamber surrounding the cylindrical shell, charging and discharging doors at opposite ends of the cylindrical shell,

an inclined track within the oven extending from the charging to the discharging end of the oven adapted to receive the articles to be treated and for automatically advancing the articles to be treated from the charging to the discharging ends of the oven, and pivoted movable means mounted within the oven for guiding the articles on the track.

7. An annealing furnace comprising a stationary cylindrical metal shell forming an oven supported by the masonry work of the furnace and inclined downwardly from the charging to the discharging ends of the oven, a heating chamber surrounding the cylinburner for supplying heated, gases to the j within the, oven onwhich annular articles are heating chamber, a damper for controlling the flow of off gases from the'heating chamber, a track within the oven extending from thecharging to the discharging ends ofthe oven adapted to receive and support annular articles to be heat treated and for automatically advancing the articles from the charging to the discharging ends of. the oven, and means mounted within n the oven above the track for guiding the articles on the-track.

8. Anannealing furnace comprisingastationaryinclined cylindrical shell forming an oven, charging'and discharging doors at opposite ends of the oven, an inclined track adapted tobe'automaticallyfed forward from the charging to thedischarging ends of" the oven, andmeans in the ovenabove the track for guiding the articles onthe track.

' 9.;Anannealing furnace comprislng a cyv l indrical, metal shell forming an oven supportedin themasonry work of the furnace in an inclined (position from the charging tothe dischargingends of the oven, charging and discharging doors at opposite ends of the oven, tracks within the oven,v on .which annular articles :are adapted to be automaticallyf ed forward from the charging to the discharging ends of the oven, andstationary and adjustable means for guiding the arti+ cles onthe tracks. I

10. Anannealing furnace comprising a cylindrical metal shell forming an oven sup ported in the-masonry work of the furnace in an inclined position from the. charging t the discharging, ends of the oven, a heating chamber surrounding the cylindrical metal shell, a combustion chamber for supplying heated gases to the heating chamber, a fram.- ing in the oven, tracks supported by thefraniing on which annular articles areadapted Y tobe automatically fed forward from the charging to the discharging ends of the oven,

and stationary and adjustable means for guiding the articles on the tracks;

' 11. An annealing furnace comprising a cylindrical metal shell formingan oven and supported in the masonry workof the ,fur-V nace inan inclined position from the charging end downwardly to the discharging end of the oven, a heating chamber surrounding the cylindrical metal shell, combustioncham bers having; flue connection with the heating chamber, a'burner, in each ofthe combustion chambers for supplying heated gases to V V the heating chamber, a port opening between the heating chamber and the stack'conduit ing to the'dischargeends ofthe oven on which annular articles areradapted to be automatically fed forw-ardrfrom the charg ing to the discharging endsof the oven, and r stationaryand adjustable means for guiding the articles being heattreated on the track,

, 12. An annealing furnace comprising a cylindrical metal shell forming an oven and supported in the surrounding masonry work of the furnace in an inclined position from the charging end downwardly to the dis chargingcend of the oven, a heating -cham-' ber surrounding the cylindrical metal shell,

combustion chambers beneath the heating chamber each having a a burner mounted therein and having a flue connection, to the heating chamber for supplying heated gases tothe heating chamber, a stack conduit, a-

plurality of port openings'betweenthe heating-chamber and the stack conduit for the Oh gases of combustion, a damper for each port opening for controlling the flow of off gases, tracks in the-oven extendingfrom the charging to the discharge ends of the oven on 13.. An annealing furnace comprisingasta-f tionary cylindrical metal shell forming an oven and supported: in the surrounding masonry'work of the. furnacein an inclined position from the charging to the. discharge ing endsoftheoven, a heating chamber surrounding the cylindrical metal shell, means for supplyingheated gases to the heating chamber, charging and discharging doors at opposite ends of the oven, aframing in the oven, tracksfor receiving and supporting an nular articles to be heat treated supported by the framing each having an upwardly bent portion at its lower end adapted toengage a bumper extending through the lower end of the shell, a stationary and movable guide on each side of the tracks for guiding the annular articles to'be heattreated, said tracks being inclined and adapted for automatically advancingthe articles through the oven, and means for adjusting the movable guides;

14.'An annealing furnace comprising. a cylindrical metal shell forming an oven and supported at theyends in the surrounding masonry work of the furnace in an inclined position from thegchar'ging-to the discharging end of the oven, aheating chamber surroundingthe cylindricalmetal shell, means for supplying heated gasesto the heating; chamber,

charging and discharging doors at opposite ends of the oven, a cradle at the charging end of the oven adapted to receive annular-articles to be fedinto the oven, adjustable guides for the annular articlesonthe cradle, a framing in the oven, tracks for receiving and support? ing the annular articles tobe treated sup ported by the framing,-said tracks being inclined for automatically advancing the annular articles in the oven, a brake for controlling the advancing movement in the oven of the annular article being heat treated, a stationary and a movable guide on each side of'the tracks for the annular articles to be heat treated, and means for adjusting the movable guides and for holding the said movable guides in their adjusted positions.

15. An annealing furnace comprising an inclined cylindrical shell forming the oven, a heating chamber surrounding the cylindrical shell, means for supplying heated gases of combustion to the heating chamber, charging and discharging doors at opposite ends of the cylindrical shell, a track in the oven between the charging anddischarging ends of the oven adapted to receive stock to be treated, a fixed guide on each side of the track, a movable guidezon each side of the track adapted for verticaland longitudinal movement, a vertically movable block slidably engaging the ends of each movable guide and means for vertically guiding the movable blocks.

16. An annealing furnace comprising an inclined cylindrical shell forming the oven, a heating chamber surrounding the cylindrical shell, means for supplying heatedgases of combustion to the heating chamber, charging and discharging doors for the ovenv at opposite ends of the cylindrical shell, a framing within the oven, tracks in the oven between the charging and discharging ends of the oven adapted to receive annular articles to be heat treated, a fixed guide on each side of each track, a movable guide oneach side of the track pivotally connected to the framing adapted for vertical and longitudinal movement, a block slidably engaging the ends of each guide and vertically movable with the guides, a linked parallel motion device attached to each block, and means for vertically guiding the movable blocks.

17. An annealing furnace comprising a cylindrical shell forming an oven, a heating 0 amber surrounding the cylindrical shell, a combustion chamber beneath the heating I chamber and separated therefrom by means of an arched roof, a flue leading to the heating chamber, from the combustion chamber, a course of insulating material in the arched roof between the combustion chamber and the heating chamber, a burner in the combustion chamber adapted to supply heated gases of'combustion to the heating chamber, means for conducting the heated gases around'the cylindrical shell, a port opening between the heating chamber and a conduit leading to a stack for the off gases, and means'for controlling the flow of the off gases. I

18. An annealing furnace comprising an inclined cylindrical shell forming an oven supported at each end in the surrounding masonry work of the furnace, a heating chamber surrounding the cylindrical shell,

a pluralityof combustion chambers beneath the heating chamber each separated therefrom by means of an arch shaped roof between the combustion chamber and the heating chamber, a course of insulating material in the arched roof between the combustion chamber and the heating chamber, a burner in each of the combustion chambers adapted to supply heated gases of combustion to the heating chamber surrounding the shell, means for conducting the heated gases around the cylindrical shell, port openings between the heating chamber and a conduit leading to a stack for the off gases, and means for controlling the flow ofofl' gases. I

19. An annealing furnace comprising a stationary inclined cylindrical shell forming an oven, masonry work surrounding the inclined cylindrical shell and for supporting it at each end, a heating chamber surrounding the shell, means for supplying heated gases of combustion to one side of the heating chamber above the oven, means provided for conducting the heated gases of combustion around'the oven, means provided below the oven for discharging the heated gases of combustion, and means for anchoring one end of the cylindrical shell and for allowing for the expansion and contraction of the opposite end of the cylindrical shell.

20. An annealing furnace comprising an inclined cylindrical metal shell forming an oven, a pair of charging and discharging doors at opposite ends of the shell, tracks having guides at each side within the oven between the charging and discharging doors on which annular articles are adapted to roll, means for dividing the lower portion of the shell between the discharging doors, cradles at the charging end of the shell for receiving the annular articles to be heat treated, said tracks being inclined for automatically feeding the annular articles from the charging to the discharging end of the shell, and a brake above each track for engaging or stop ping the automatic feed of the annular articles treated.

21. An annealing furnace comprising an inclined cylindrical metal shell forming an oven, a pair of charging and discharging doors at opposite ends of the shell, tracks within the oven between the charging and discharging doors on which annular articles are adapted to roll, a fixed and amovable guide at each side of each track, a plate for dividingthe lower portion of the shell between the discharging doors, cradles at the chargingend'of the shell having adjustable guides for receiving the annular articles to be heat treated, said tracks being inclined for automatically feeding the annular articles from the charging to the discharging end of the shell, a brake above each track in the oven near its lower end each comprising a bar pivoted at one end to the shell, the oppo- 40 stopping the automatic feed of the annular opposite ends of the shell, framingwithin site end of the bar being vertically and adjustably movable and adapted for engaging or stopping the automatic feed of the annular articles heat treated.

22. An annealing furnace Comprising a metal shell forming an oven, a heating chamber surrounding the metal shell, a track within the shell for receiving and supports ing articles to be heat treated, charging and doors at opposite ends of the shell, track rails within the oven between the charging and (l1SCl121Igl1lgfil00IS on which annular ELIiZlClQS are adapted to roll, said track "rails having upwardly bent end'portions at the discharging end of the shell engaging butiersextending through opening in the end of the shell,

a fixed and a movable guide at-each side of V each track rail, a plate for dividing the lower portion of the shell between the discharging the oven, inclined tracks supported by the framing in the oven on which annular art-icles are supported and adapted to roll from the charging to the discharging end of the shell, stationary guiding means on each side of each track for guiding the lower portions of the annular articles on the tracks, vertically and longitudinally adjustable guide bars pivotally connected to the framing in the oven for guiding the upper portions of the annular articles on the tracks, a block slidahly engaging the end of each adjustable guide bar adapted for vertical movement with the guide bars, a parallel motion device having pivoted connections between each block and the shell for keeping the blocks in 2 vertical alignmentat right'angles to the axis of the shell, means for guiding the ends of the blocks, a heating chamber surrounding the cylindrical shell, combustion chambers each havinga burner therein for supplying heated gases of combustion to the heating chamber, and port openings in the heating chamberfor the oil gases of combustion.

In testimony whereof I hereunto afiix' my signature.

RICHARD H. STEVENS.

doors, cradles at the charging end of the shell ,7

having adjustable side guides for receiving annular articles to be heat treated, said track rail being inclined for automatically feeding the annular articles by gravity from the charging to the discharging end of the shell,

a brake above each track rail in the oven near the lower end each comprising a bar pivoted at one end to the shell the opposite end of each bar being vertically and adjustably movable and adapted for engaging or articles heat treated. 24. An annealing furnace comprising an inclined cyhndrical shell forming an oven,

framing within the oven, tracks supported by the framing in the oven on which annular articles are supported and 'are adapted to roll from thecharging to the discharging end of the shell, stationary guiding means on each side of each track for guiding the lower portions of the annular articles on the tracks,

vertically and longitudinally adjustable I guide bars pivotally connectedito the framing in the oven adapted to swing through an are parallel to the axis of the shellfor guiding the upper portions of the annular articles on the tracks, a block slidably engaging the end of each adjustable guide bar adapted for vertical movementywith the guide bars and means for guiding the vertical movement of the blocks. 7 e

25. An annealing furnace comprising a stationary inclined cylindrical shell forming an oven, charging and dischargingdoors at detriment]; 0F Gammon.

Patent No. 1,848,281. Granted March 8, 1932, to

RICHARD H. STEVENS.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 3, line 112, strike out the words this operation ofcharging wheels" and insert instead entirely,

, the next wheel charged; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 26th day of April, A. D. 1932.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

